A granular body grinding device is for grinding surfaces of granular bodies being in the form of sands and is for generating grinding powder being particulates which are generated by removing extraneous matters adhering to the surfaces of granular bodies or by grinding material granular bodies. As one applying the granular body grinding device thereto, there has been known a device that makes foundry sands reusable by removing coal powder and resin adhering to the surfaces of used foundry sands. For example, a foundry sand reclamation device described in Patent Document 1 is provided with a plurality of grinding wheels mounted in juxtaposition on the same drive shaft and a drum for scooping up foundry sands in the device. In the device, the foundry sands charged into the device are scooped up by the drum above the rotating grinding wheels and are repetitively ground on the circumferential surfaces being grinding surfaces of the grinding wheels.
Further, a foundry sand reclamation device in Patent Document 2 is provided with a rotor formed with inclined rough surfaces (grinding surfaces) on its rotating surface and a mixing tub that forms a fluidized bed of foundry sands inside thereof by blasting air from a blower, as described in paragraphs [0041], [0042] and FIG. 2. In the device, the foundry sands charged into the device are fluidized in the mixing tub and are ground by being collided with the rough surfaces of the rotationally driven rotor. As described above, the devices in Patent Documents 1 and 2 perform the removals of extraneous matters on the foundry sands by grinding the surfaces of the foundry sands.